I've been seeing a lot about fin ray technology for simulating realitic movements that are more smooth.Look up the company Festo.

You can take the concepts and improve on it. You can replace the arm servos with two air pumps and a strong balloon or spring to simulate the muscles.Think magnets for compression of the spring. Here is a link to making your own servo, with this principle, you can cut costs and do similar things:

- Use Styrofoam for all parts. This will be great for initial molds.- Use Sponges for movement layers.- Use fishing line for pulling in a tense line. Run the wire through the middle.- Use water pumps and suckers to modulate the movement of certain devices.- Utilize springs and magnets in a tube in order to make a make-shift pump.

Make An Actuator Servo Youtube Clip:

Interesting Links:-

this is what I am doing for my robot since I ran out of money cause of school and i hate using credit cards. Also, I was thinking of doing most of the processing in a remote computer (like your central brain) in order to reduce power consumption.

Look at how Festo designed their moving hand. It is so clean in it's movements. You can alter the concept using fishing like.

Air muscle is not so practical after all..Motors to wind up tense line hook to a tendon would still be cheaper.Will still work with just switches if you consider to place 5 mini motors on one tendon, active the amount of motor for the amount of force.

I do have a idea of an ideal skeleton for this kind of movement.Imagine ball-joint of dollfies, but this does not hold together. The tendons will hold the joint to another. When there's enough tendon connections + when all motor fully winded up all the strings, I would imagine the joint will be hold in place.I would imagine, more motors on one tendon will bring fast movement aspects.